carbon atom

Carbon-carbon bond

A carbon-carbon bond is a covalentbond between two carbonatoms . The most common form is the single bond – a bond composed of two electrons, one from each of the two atoms. The carbon-carbon single bond is a sigma bond and is said to be formed between one hybridized orbital from each of the carbon atoms. In ethane, the orbitals are sp3hybridized orbitals, but single bonds formed between carbon atoms with other hybridisations do occur (e.g. sp2 to sp2). In fact, the carbon atoms in the single bond need not be of the same hybridisation. Carbon atoms can also form double bonds called alkenes or triple bonds called alkynes. A double bond is formed with an sp2hybridized orbital and a p-orbital that isn't involved in the hybridization. A triple bond is formed with an sp hybridized orbital and two p-orbitals from each atom. The use of the p-orbitals forms a pi bond.

Carbon has the unique characteristic among all elements to form long chains of its own atoms, a property called catenation. This coupled with the strength of the carbon-carbon bond gives rise to an enormous number of molecular forms, many of which are important structural elements of life, and so carbon compounds have their own field of study: organic chemistry.

Branching is also common in C-C skeletons. Different carbon atoms can be identified with respect to the number of other carbon neighbors:

primary carbon atom: one carbon neighbor

secondary carbon atom: two carbon neighbors

tertiary carbon atom: three carbon neighbors

quaternary carbon atom: four carbon neighbors

Synthesis

Carbon-carbon bond forming reactions are organic reactions in which a new carbon carbon bond is formed. They are important in the production of many man-made chemicals such as pharmaceuticals and plastics.